Drawn and ironed containers

ABSTRACT

A tool pack assembly for an ironing press for forming thinwalled container bodies including a die block having an open slot herein for receiving a plurality of ironing rings which are secured in the die block by means of an axially expandable hollow jack screw, with the die orifices in the rings in co-axial alignment with the press mandrel. Spacer rings are provided between the ironing rings and have means associated therewith for introducing lubricant around the entire periphery of the container body prior to movement of the body through successive ironing rings.

D United States Patent 1 9 Dunn 1451 Apr. 4, 1972 [541 DRAWN AND IRONEDCONTAINERS 3,399,558 9/1968 Smith et a1 ..72/468 [72] Inventor: Lhyd G.n Lower Butte, Pa. 1,370,116 3/1921 Johnson ..72/467 [73] Assignee:Aluminum Company of America, Pitty Examiner-Richard Herb-5! sburgh, Pa.Attorney-David W. Brownlee [22] Fllfldi Mil- 17, 1970 Appl' 20,268 Atool pack assembly for an ironing press for forming thinwalled containerbodies including a die block having an open 52 us. Cl. ..72/349, 72/467herein 8 a plurality 8 "I! which [51] "521d 22/28 secured in the dieblock by means of an axially expandable [58] Field of Search ..72/349467 468 347 34s with die alignment with the press mandrel. Spacer ringsare provided between the ironin rin and have means associated 56 R l t 88 1 l 1 e Cl ed therewith for introducing lubricant around the entireUNITED STATES PATENTS periphery of the container body prior to movementof the body through successive ironing rings. 1,742,795 1/1930 Tanner..72/349 3,359,775 12/1967 Langewis ..72/344 8Clnims,4Drawlng Figures e032 22 2, I] I] I" 2s 22 JEN v 4o T 33 if 29* Z 3/ 3o 4, 4 20 ze "2aPATENTEDAPR 4 m2 SHEET 1 [IF 2 FIG.

FIG. 2.

INVENTOR. LLOYD 6. DUNN Attorney DRAWN AND IRONED CONTAINERS BACKGROUNDOF THE INVENTION In forming thin-walled container bodies, it isconventional to provide a plurality of ironing or drawing rings throughwhich each container body is moved to thin and elongate its side wall.Continuous operation of an ironing press results in considerable wear ofthe ironing face of such rings and requires replacement of the rings atregular intervals. Accordingly, it is desirable to provide ironing ringsthat may be easily and quickly removed, replaced and aligned. It is alsodesirable to provide a convenient means for introducing lubricant intoan ironing ring tool pack assembly for lubricating the rings and thecontainer body as it moves therethrough. l-leretofore, a variety ofsystems have been employed for securing drawing or ironing rings in apress, including positioning the rings in a die carrier as shown in Boltet al. U.S. Pat. No. 3,203,218, locking the dies in a pair of leaf-likeelements as shown in Smith et al. U.S. Pat. No. 3,399,558, andpositioning the dies in a series of longitudinal spaced transverse slotsor grooves as shown in Smith U.S. Pat. No. 1,977,327. However, none ofthese systems have proven to be completely satisfactory from thestandpoint of speed of tool change and accuracy of co-axial alignment ofthe die orifices with the press mandrel. Accordingly, an improved toolpack assembly that facilitates quick and easy replacement and alignmentof ironing rings is desirable.

SUMMARY OF THE INVENTION The invention provides a tool pack assembly foran ironing press which includes a die block having an open slot thereinand an apertured cap at both ends of the slot, and having a plurality ofironing rings disposed in the slot with spacerlubricators therebetween.An axially expandable hollow jack screw is disposed in the slot forlocking the draw rings in position in co-axial alignment with the pressmandrel. The ironing rings and spacers in such a tool pack assembly canbe quickly and easily changed by contracting the jack screw to releasethe rings and spacers so that worn rings can be lifted out of the slotfor replacement with new ones.

Accordingly, it is an object of this invention to provide an improvedtool pack assembly for an ironing press.

Another object of the invention is to provide a tool pack assembly foran ironing press in which the ironing rings can be changed quickly.

A further object of the invention is to provide a tool pack assemblywhich facilitates quick and accurate co-axial alignment of the dieorifices in the ironing rings with the press mandrel.

Another object of the invention is to provide a tool pack assembly whichfacilitates lubrication of the container body during ironing.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects andadvantages of the invention will be more fully understood andappreciated with reference to the following description and drawingswherein:

FIG. 1 is a top plan view illustrating an ironing press with an improvedtool pack assembly secured therein;

FIG. 2 is an enlarged top plan view of the tool pack in the ironingpress of FIG. 1;

FIG. 3 is a cross-section elevational taken along line III-III of FIG.2; and

FIG. 4 is a cross-section elevational taken along line IV--IV of FIG. 2.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring to FIG. 1, an ironingpress, generally indicated by the numeral 10, is illustrated including apress bed 12 and a reciprocating mandrel or ram 14, and having aremovable tool pack assembly 16 secured in the press bed. Referring toFIGS. 2-4, the tool pack assembly 16 comprises a steel die or holderblock 18 with an open slot 20 therethrough for receiving ironing rings22. The block 18 serves as a bridge from the press frame or bed toprovide a rigid structure to maintain the rings 22 in positive alignmentwith ram 14. Preferably, slot 20 is U- shaped with an arcuate bottom,and for a horizontal press like the one selected for illustration, opensupwardly to facilitate access to the slot from the top of the press. Dieblock 18 may be secured on the press bed 12 with the comers of the pressbed projecting into mounting recesses in the side of the die block, andwith means such as bolts 26 securing the die block to the press bed.With the die block secured to the press bed, slot 20 in the die block isin alignment with the press mandrel 14. This alignment can beaccomplished by a variety of means such as by machining the matingsurfaces of the die block and press bed, by shirnming between the dieblock and press bed or by providing adjustable bolts and tapered matingsurfaces on the press bed and the die block for relative positioning ofthe same. Preferably, holder block 18 is heat treated and stabilizedbefore final grinding for accurate positioning and ring alignment.

Die block 18 has centrally apertured caps 24, 25 or other retainingmeans, secured to it on the ends of slot 20 by means of bolts 28. Endcaps 24, 25 and die block 18 are machined so that the end caps fit onthe die block with the faces on the end caps square or perpendicular tothe inner surface of the slot 20 in the die block and to thelongitudinal axis of ram 14. A sizing or pre-draw ring 29 may be locatedin the aperture in the front end cap 24 on the entrance end of the dieblock 18, and mechanical strippers 31 may be located in the aperture inthe rear end cap 25 as is hereinafter described.

Tool pack assembly 16 preferably includes three ironing rings 22, aspacer ring 32, two spacer-lubrication rings 34 and a hollow jack screw36, all of which are transversely disposed in the slot in the die block.However, more or fewer ironing rings and spacer-lubricators may beemployed as desired. Ironing rings 22, selected for illustration, eachcomprises a steel ring 30 which is shrink fitted on a carbide insert 33.The steel ring 30 is preferably large enough in diameter and has asuflicient section mass to resist significant expansion of the ring dueto the stresses produced therein during ironing. A conventional carbideinsert 33 has a die orifice therethrough including an entry portion 38,a land 40 and a relief portion 41, although various other known ringprofiles may be also employed. Inasmuch as the ironing rings aredesigned to progressively thin the .wall of a container as it movestherethrough on mandrel 14', the die orifices are of decreasing diameterprogressing from the first ring adjacent the entrance end of the toolpack to the third ring adjacent the exit end of the tool pack.Typically, the inside diameter of the working land 40 of each of therings is a few thousandths of an inch less than the diameter of themandrel plus the double thickness of the container wallas it enters suchring.

Preferably, the rings are spaced so that a container body will be workedor ironed by only one ironing ring 22 at any one time. The rings aretherefore spaced so that a container body will have moved completelythrough the working land 40 of the preceding ironing ring before movinginto the working land of the next ring. Since the wall of the containeris elongated as it is ironed, rings 2 and 3 are spaced further apartthan are rings 1 and 2 in order to avoid working of the container wallin more than one ironing ring at any one time. Such spacing depends onthe length of the cup being ironed, the side wall thickness of the cup,and the precent reduction in thickness of the side wall which is beingeffected. Spacer 32, lubrication rings 34 and jack screw 36 are selectedwith appropriate thicknesses to properly space the ironing rings 22. Toallow for thermal expansion of the rings and for alignment of the ringsin slot 20, a small radial clearance is provided between the rings andthe sides of the slot. With rings approximately 6 inches in diameter, aradial clearance of approximately 0.0025 inch has been found to providean adequate clearance for such purposes.

Jack screw 36 is adapted to be axially expanded and contracted to lockthe ironing rings 22, spacers 32, 34 and jack screw 36 in the slot 20between end caps 24, 25 and comprises a sleeve 42 which is threaded at44 for assembly with a collar 46. By turning collar 46 relative tosleeve 42, the jack screw can be axially expanded and contracted toeither lock the assembly together or release the assembly forreplacement of rings. Adjustment holes 48 are provided in sleeve 42 andcollar 46 to facilitate such relative rotation of the members.

The front end cap 24 and each lubrication ring 34 has a feed holetherein which communicates with an annular lubrication chamber 52 and anannular feed passageway 54 around the die orifice. The feed passageway54 is narrower than is chamber 52 to ensure that lubricant is suppliedonto the surface of a container body around its complete periphery aswill be hereinafter explained. Lubrication lines are attached to thefeed holes in the lubrication rings, and drain slots 56 are provided inspacer 32 and jack 36 for draining lubricant, and extraneous mattercarried by the lubricant, through drain openings 58 in the die block andinto a drain tank or the like not shown. Extraneous matter carried bythe lubricant may include dirt andparticles or fragments of thecontainer bodies which may be clipped therefrom during ironing.

The tool pack assembly further includes a cover plate 60 with a handle62 attached thereto. This plate 60 is positioned over the rings andspacers in slot 20 in the die block 18, and is secured on the die blockby means of bolts 64. Referring to FIG. 2, cover plate 60 is partiallycut away to provide access to the lubrication feed holes in lubricationrings 34 and to the adjustment holes in jack 36. Cover plate 60 isdesigned primarily to be a safety shield over the rings.

Heretofore, tool pack assemblies have required considerable time tochange ironing rings since they have had no quick and easy means forsecuring and aligning the rings in the assemblies. Tool pack assemblieshave usually required removal and/or disassembly of the complete toolpack in order to change either one ironing ring or all the ironingrings.'The lubrication connections and the locking and alignment meansprovided in such assemblies have made it difficult to change tools inless than 10 to 15 minutes. The present invention greatly simplifiestool changes and has permitted reducing the time for such changes toapproximately two minutes or even less. In the present invention, anyone or all of the ironing rings can be removed and replaced withoutcomplete removal and/or disassembly of the entire tool pack.

To change ironing rings in the tool pack 16 of the invention, the twobolts 64 on the cover plate are removed and the cover plate is liftedoff the die block 18. Jack screw 36 is then contracted to free the jackscrew and the rings so that worn or broken ironing rings can be liftedout of the slot in the die block and replaced with new rings. Ifdesired, the lubrication rings 34 may also be lifted out of slot 20,with or without the lubrication lines attached, but such removal is notnecessary for changing ironing rings. Preferably, the slot 20 and theironing rings 22 are sufficiently close in relative diameters for therings, as loosely positioned in the slot, to be in approximate alignmentwith the mandrel, but leaving a smallclearance around the rings so thatthey can shift and/or expand in the slot. A radial clearance ofapproximately 0.0025 inch between the rings and the slot has been foundto provide sufiicient space "fo'r thermal expansion of the rings aspreviously discussed and to provide the desired preliminary alignmentwith space for shifting into final co axial alignment with the mandrel.Alternatively, auxiliary means such as shims or the like maybe providedfor effecting approximate initial alignment of the rings in theslot'oWith new ironing rings positioned in slot 20 in approximate alignmentwith mandrel l4, jack screw 36 is partially expanded to a point wherethe rings are held snugly in position, but loose enough for them toshift in response to a positive force applied thereagainst. Mandrel 14with a container body thereon is then run through the die assembly.Since the ironing rings are free to shift, running the mandrel andcontainer body through the rings effects automatic centering of therings about the mandrel and workpiece. Thereafter, jack screw 36 isfurther axially expanded to lock the entire assembly together with theironing rings in perfect co-axially alignment with the mandrel. Thiscentering can also be accomplished while the press is in operation sinceaccess has been provided to the locking jack screw.

The tool pack assembly 16 and the mandrel 14 may be connected to alubricant supply system, not shown, which is employed primarily toreduce friction during ironing, but which may also be used to controlthe temperature of the mandrel and ironing rings. Accordingly, thesystem may include means for heating or cooling the lubricant duringoperation, as well as means for cleaning the lubricant. Preferably, thelubricant is initially heated prior to commencement of ironing and thencooled during continuous operation to maintain the lubricant, and thusthe tools, at a relatively constant temperature. One suitable lubricantthat has been used is an emulsion of oil in water, but the invention isnot limited to the use of such lubricant. The lubrication system mayinclude various pumps, filters, gauges, valves and lubrication lineswhich are connected to the front end cap, the lubrication rings and themandrel for circulation therethrough.

As illustrated in FIG. 3, the front end cap 24 and the two lubricationrings 34 are particularly adapted for supplying lubricant around theentire periphery of a container body as it moves through the tool packassembly. The provision of an annular chamber 52 in the rings followedby an annular passageway 54 which is narrower than chamber 52 assuresthat the chamber will be completely filled with lubricant forapplication to the surface of a container via passageway 54. The narrowpassageway produces a pressure differential between the chamber 54 andthe mouth of the passageway, which in turn causes the lubricant tocompletely fill the chamber for supply around the entire periphery of acontainer.

The mandrel 14 may also have a passageway through it which is connectedto an airline and to either the atmosphere or a vacuum system forventing of the inside of a drawn cup as mandrel 14 is moved into thecup, and to a compressed air system to effect stripping of an ironedcontainer from the mandrel at the completion of the ironing stroke asdescribed in my U.S. Pat. application Ser. No. 20,297, filed Mar. 17,1970, for Method and Apparatus for Stripping Container Bodies from aReciprocal Mandrel," and executed and filed concurrently herewith.

In operation of ironing press 10, a drawn cup is positioned, by meansnot shown, at the entrance end of the tool pack assembly, with the cupopen toward mandrel 14. The cup to be ironed preferably has an insidediameter which is approximately 0.025 inch greater than the outsidediameter of mandrel 14 so that the mandrel can be moved into the cupwithout difficulty. When the cup is in position at the entrance end ofthe tool pack assembly, lubricant from the lubrication system is sprayedonto the inner and outer surfaces of the cup. The mandrel 14 then movesinto the cup and carries it into and through the tool pack assembly 16.As the cup is carried through the assembly, pre-draw ring 29 centers thecup on mandrel l4 and draws the side wall of the cup inward. Preferablya small clearance remains between the cup and the mandrel after suchpreliminary drawing, but the pre-draw ring may, if desired, draw theside of the cup into intimate contact with the mandrel. As the cup exitsthe pre-draw. ring, additional lubricant is supplied from annularpassageway 54 around the exit end of the draw ring onto the outersurface of the cup. The cup then moves through the three ironing rings22 which progressively thin and elongate the side wall of the cup toform a container body. Additional lubricant is applied to the cup duringsuch ironing by the two lubrication rings 34. At the completion of theironing stroke, the ironed container body may be stripped from themandrel 14 by means of compressed air as is described in my aboveidentified U.S. patent application, or by other means known in the art.Mechanical strippers 31 may be provided in end cap 25 for such strippingor as a safety check for air stripping as is described in saidapplication.

It is therefore seen that the present invention provides an improvedtool pack assembly wherein the ironing rings can be quickly and easilyremoved for inspection or replacement, and which incorporates anefficient and simple lubrication system which does not interfere withtool changes. While a particular embodiment of the invention has beenillustrated and described, it will be obvious to one skilled in the artthat numerous variations and modifications can be made therein. Forexample, a hydraulic jack could be used in a tool pack assembly in placeof a jack screw so that expansion of the ironing rings, spacers, etc.due to heat or the like could be compensated for by controlling thehydraulic pressure in the jack. By controlling the pressure in ahydraulic jack, the jack could be compressed in response to expansion ofthe rings in the tool pack assembly. The end caps on the tool packassembly could also be integral parts of the die block. The slot in thedie block could be cut into the block leaving metal on both ends of theslot to retain the rings and spacers in the slot. As a substitute forthe bolts which are illustrated for holding the cover plate in place, aclamp or clamps could also be used for such purpose. The cover platecould be hinged or otherwise restrained on one edge and a clamp could beemployed to lock or secure the opposite edge of the plate againstaccidental removal.

What is claimed is:

1. In an ironing press having a press bed and a reciprocal mandrel, atool pack assembly secured to the press bed comprising:

a. a die block having an elongated open slot therein with itslongitudinal axis aligned with the press mandrel;

b. a plurality of ironing rings transversely disposed in the slot in thedie block, said ironing rings having radial dimensions which are lessthan the transverse dimensions of the slot to permit axial alignment ofthe rings in the slot;

c. apertured means at the ends of the slot in said die block forretaining said ironing rings in the slot between said means whilepermitting the press mandrel to pass therethrough; and

d. adjustable means disposed in the slot in the die block between saidapertured end means for applying pressure, either directly orindirectly, against said ironing rings parallel to the longitudinal axisof the slot to secure the ironing rings in the slot whereby they can bequickly and easily replaced and aligned.

2. A tool pack assembly as set forth in claim 1 which includes apre-draw ring secured therein on the entrance end of the assembly.

3. A tool pack assembly as set forth in claim 1 which includes at leastone centrally apertured lubrication ring in the slot in said die block.

4. A tool pack assembly as set forth in claim 3 in which the lubricationring has an annular lubrication chamber leading into an annularpassageway around the entire periphery of the central aperture in thering for feeding lubricant onto a container body as it moves through thering.

5. A tool pack assembly as set forth in claim 1 in which said aperturedretaining means at the ends of the slot in the die block have oppositelyfacing planar surfaces each of which is normal to the axis of the pressmandrel for abutment and securement of said ironing rings against saidsurfaces in axial alignment with the mandrel.

6. A tool pack assembly as set forth in claim 1 in which a small radialclearance is provided between said ironing rings and the slot in the dieblock.

7. A tool pack assembly as set forth in claim 1 in which the slot insaid die block is U-shaped.

8. A tool pack assembly as set forth in claim 1 in which said jack meansis a hollow jack screw.

1. In an ironing press having a press bed and a reciprocal mandrel, atool pack assembly secured to the press bed comprising: a. a die blockhaving an elongated open slot therein with its longitudinal axis alignedwith the press mandrel; b. a plurality of ironing rings transverselydisposed in the slot in the die block, said ironing rings having radialdimensions which are less than the transverse dimensions of the slot topermit axial alignment of the rings in the slot; c. apertured means atthe ends of the slot in said die block for retaining said ironing ringsin the slot between said means while permitting the press mandrel topass therethrough; and d. adjustable means disposed in the slot in thedie block between said apertured end means for applying pressure, eitherdirectly or indirectly, against said ironing rings parallel to thelongitudinal axis of the slot to secure the ironing rings in the slotwhereby they can be quickly and easily replaced and aligned.
 2. A toolpack assembly as set forth in claim 1 which includes a pre-draw ringsecured therein on the entrance end of the assembly.
 3. A tool packassembly as set forth in claim 1 which includes at least one centrallyapertured lubrication ring in the slot in said die block.
 4. A tool packassembly as set forth in claim 3 in which the lubrication ring has anannular lubrication chamber leading into an annular passageway aroundthe entire periphery of the central aperture in the ring for feedinglubricant onto a container body as it moves through the ring.
 5. A toolpack assembly as set forth in claim 1 in which said apertured retainingmeans at the ends of the slot in the die block have oppositely facingplanar surfaces each of which is normal to the axis of the press mandrelfor abutment and securement of said ironing rings against said surfacesin axial alignment with the mandrel.
 6. A tool pack assembly as setforth in claim 1 in which a small radial clearance is provided betweensaid ironing rings and the slot in the die block.
 7. A tool packassembly as set forth in claim 1 in which the slot in said die block isU-shaped.
 8. A tool pack assembly as set forth in claim 1 in which saidjack means is a hollow jack screw.